Recent studies suggest that patients with stroke may benefit if medical care begins as soon as possible after the onset of symptoms. The goal of this research project is to evaluate pre- hospital care of acute stroke patients in Seattle, Washington. In this population based study we will identify and characterize all patients admitted to a hospital in Seattle from 1990 through 1994 and discharged with a diagnosis of acute ischemic or hemorrhagic stroke using the Comprehensive Hospitals Abstract Reporting System (CHARS) databases maintained by Washington State. Next we will identify and characterize all patients treated by pre-hospital emergency medicine personnel using databases maintained by the Medic One organization and Shepard Lifefleet, a private ambulance company. The databases will be merged, allowing determination of: 1) the proportion of all patients with a hospital discharge diagnosis of stroke who are treated by pre-hospital emergency medical personnel; 2) the sensitivity, specificity and predictive values of a pre-hospital diagnosis of stroke relative to the hospital discharge diagnosis.